High-Dose Diazepam Controls Severe Dyskinesia in Anti-NMDA Receptor Encephalitis.

Abstract

Because there is no standard treatment to control dyskinesia in anti-NMDA receptor (NMDAR) encephalitis, we analyzed the therapeutic efficacy of high-dose diazepam in dyskinesia associated with NMDAR encephalitis. We reviewed patients with NMDAR encephalitis with dyskinesia who were admitted to Seoul National University Hospital between November 2012 and July 2018. High-dose diazepam was administered orally or via a nasogastric tube 3-6 times a day. We assessed the treatment effect by comparing dyskinesia severity between the first day of the highest dose of diazepam and one week after the treatment. Among 68 patients with NMDAR encephalitis during the study period, 33 patients were treated with enteral diazepam (ranging from 6 to 180 mg) to control dyskinesia, along with immunotherapy. The severity of dyskinesia improved from average grade 2.4 ± 0.6 to 1.1 ± 0.7 after 1 week of the highest dose of diazepam (mean severity change -1.4 ± 0.6, 95% confidence interval -1.2 to -1.6; p < 0.001). No patients had serious adverse events except for mild sedation. Dyskinesia in NMDAR encephalitis improved after treatment with enteral diazepam without significant side effects. This study suggests that enteral diazepam could be a treatment option for control dyskinesia in NMDAR encephalitis. This study provides Class IV evidence that for patients with dyskinesias associated with NMDAR encephalitis, enteral diazepam is effective and safe in dyskinesia control.